Nested Relational Query Returns Empty Arrays (Including Admin Panel Filtering)

[Kenji-Nguyen]

Hi everyone

I encountered an issue where querying nested relational properties returns an empty array. This previously worked in earlier versions:

Before update

"next": "15.0.0-canary.104",
"payload": "3.0.0-beta.91"

After update (issue encountered)

"next": "15.0.3",
"payload": "3.4.0"

Additional environment info

• MongoDB
• Chrome

Code Example

Function: Query apartments filtered by a relational location's slug field.

export const getApartmentBySlug = async (
  locationSlug: string,
  options?: { locale?: string; draft?: boolean },
) => {
  const payload = await getPayload({ config });

  console.log(`Fetching apartments for location: ${locationSlug}`);

  const { docs: apartments } = await payload.find({
    collection: "apartments",
    where: {
      "location.slug": {
        equals: locationSlug,
      },
    },
    depth: 2,
    locale: validateLocale(options?.locale),
    limit: 1000,
    sort: "priority",
  });
  console.log("Apartments:", apartments);

  return apartments;
};

Expected Behavior:

The function should return all apartments where location.slug matches the locationSlug parameter.

Current Behavior:

The docs array is empty ([]), even though apartments with the specified location.slug exist in the database.

Admin Panel Issue:

When trying to filter apartments by the location relation in the admin panel, no results are returned.

Steps to Reproduce

1. Schema:

• Location has a slug field (string).
• Apartment has a relational field pointing to Location.

2.Run Query:

• Call the getApartmentBySlug function with a valid locationSlug where data exists.

3. Observe Behavior:

• Query returns an empty array.
• Filtering in the Payload admin panel by location also returns no results.

---

Appendix

Before update ✅

Console:

Fetching apartments for location: franklinstrasse
Query for location: franklinstrasse
Apartments: [//returns 5 objects]
 GET /en/locations/zurich/franklinstrasse 200 in 17363ms

Admin Panel:

Admin Panel after location filter applied: ✅

---

After update (issue encountered) ❌

Console:

Fetching apartments for location: franklinstrasse
Query for location: franklinstrasse
Apartments: []
 GET /en/locations/zurich/franklinstrasse 200 in 3170ms

Admin Panel:

Admin Panel after location filter applied: ❌

Data entry in database

[Kenji-Nguyen]

Solution is found here:
https://discord.com/channels/967097582721572934/1324460994906558504/1326256604819226624

Quoting Eustachio: "I have found the answer for this, basically relationship id has to be ObjectId. From Payload V2 the relationship field (non-polymorphic) to websites was a string and in Payload V3 it is an ObjectId, once I went to each document where the websites relationship was and saved it, the field turned into an ObjectId and all the queries worked back again."